Method for sealing light engine module with flip-chip light emitting diode

Abstract

The sealing method is to firstly form a circuit layout with electrode contacts on a circuit board and flip-chip light emitting diodes (FCLEDs) are electrically connected to the electrode contacts by adhesive material. After the adhesive material is solidified, a plastic ring is attached to the circuit board to surround the LEDs and cycle dispensing is used to coat fluorescent-powder gel within plastic ring on the exposed sides of the LEDs and on the surface of the circuit board between neighboring LEDs. Then, vacuum de-aerating and baking is conducted and a light engine module is formed. In the present invention, the lateral light from the LEDs forms a light extension area where the coated fluorescent-powder gel there is activated and extended planar light is as such produced. The present invention is therefore able to increase lighting efficiency, light projection angle, light brightness, and uniformity.

1 . A sealing method to a light engine module, comprising the steps of:
 forming a circuit layout on a first side of a circuit board, said circuit layout having at least a pair of positive and negative electrodes;   attaching a plurality of light emitting diodes (LEDs) on said first side of said circuit board and electrically connecting said LEDs to said electrode contacts, each LED thereby having five exposed sides;   attaching a plastic on said first side of said circuit board, thereby defining an area encircling said LEDs; and   coating fluorescent-powder gal within said area on said exposed sides of said LEDs and the surface on said first side between neighboring LEDs;   wherein lateral light from said LEDs is overlapped and an extended planar light source is formed, thereby increasing lighting efficiency of said LEDs.   
     
     
         2 . The sealing method according to  claim 1 , wherein said fluorescent-powder gel is coated by a dispensing device with a nozzle and said fluorescent-powder gel is ejected out of said nozzle. 
     
     
         3 . The sealing method according to  claim 1 , wherein said circuit layout is also formed on a second side of said circuit layout. 
     
     
         4 . The sealing method according to  claim 1 , wherein each of said LED is a solid, rectangular chip with six sides in a flip-chip configuration. 
     
     
         5 . The sealing method according to  claim 1 , wherein said fluorescent-powder gel is made by uniformly mixing fluorescent powder and a paste at appropriate proportions. 
     
     
         6 . The sealing method according to  claim 5 , wherein said paste is a transparent or translucent adhesive paste, and is one of epoxy resin and silicone.